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In order to potentially reduce use of environmentally damaging rodenticides, integrated Pest Management (IPM) for rodents, or Ecologically Based Rodent Management (EBRM), proposes a more sustainable management approach using strategies informed by an increased understanding of rodent population and community ecology, including interactions with important predators, such as raptors. Nest boxes and perches can encourage raptor presence in agricultural areas and potentially enhance the regulatory ecosystem services provided by raptor predation of agricultural pests. To assess this idea, we studied American kestrels (widespread, generalist predators that readily use nest boxes) in a fruit-growing region of northwestern Michigan. The most common mammal prey in the diets of these kestrels from 2013 through 2016 were voles, which are considered the most important rodent pests in temperate fruit orchards. We utilized live trapping to measure small mammal abundances and activity during the summer at sites with and without active kestrel nest boxes; furthermore, we utilized camera trapping to measure small mammal presence during the winter, when damage to trees is most likely. As predicted, small mammal abundance and activity was lower at orchards with active kestrel boxes and at orchards that had been more recently mowed; however, these differences did not carry over as differences in winter presence in orchards. Our sampling demonstrated that voles were absent from orchards during both summer and winter, which suggests that orchards offer insufficient cover except under certain conditions, such as sustained snow cover. Instead, mice were the most abundant small mammals in most orchards during the summer and were also present during the winter. More evidence is therefore needed to determine the extent of orchard damage attributable to Peromyscus spp. and whether indirect effects of kestrels on Peromyscus spp. may reduce damage. We provide recommendations for future research on the effects of raptor predation in orchards.

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Abstract: Suppression of pest species via a native predator is a regulating ecosystem service that has the potential to limit crop damage and produce economic benefits. American kestrels Falco sparverius are widespread, highly mobile, generalist predators that hunt in human‐dominated habitats and have the potential to provide previously undocumented ecosystem services in agricultural landscapes. We hypothesized that kestrel activity associated with nest boxes and artificial perches acts to increase perceived predation risk that, in combination with direct predation, can reduce fruit‐eating bird abundances in orchards. We used counts and observations of fruit‐eating birds from fixed‐width transect surveys to investigate variation in bird abundances and to estimate sweet cherry loss in cherry orchards with and without active kestrel boxes. We also conducted a benefit–cost analysis of nest box installation and used regional economic modelling to estimate macroeconomic impacts of increased sweet cherry production in Michigan, an important US fruit production region. Fruit‐eating bird counts were significantly lower at orchards with active kestrel boxes. Although kestrels used the perches in young orchard blocks and may benefit from them, the presence of perches did not have a significant effect on bird counts. Benefit–cost ratios for kestrel nest boxes indicated that for every dollar spent on nest boxes, $84 to $357 of sweet cherries would be saved from fruit‐eating birds. Regional economic modelling predicted that increased sweet cherry production from reduced bird damage would result in 46–50 jobs created and $2.2 million to $2.4 million in increased income for the state of Michigan over a 5‐year period. Synthesis and applications. Kestrel nest boxes in sweet cherry orchards provide a highly cost‐effective ecosystem service with potential reverberating benefits for a regional economy. Box occupancy rates will undoubtedly vary across landscapes and regions. However, costs to install and maintain boxes are small and, even if box occupancy rates are low, boxes can direct kestrel activity to particular places in agricultural landscapes where they can deter pest birds. Thus, the potential benefits for fruit crops greatly outweigh the costs of this pest management strategy. [ABSTRACT FROM AUTHOR]

Installation of nest boxes for a declining raptor species, the American Kestrel ( Falco sparverius), in agricultural areas may benefit both local kestrel conservation and management of prey species that cause damage to crops. Kestrels responded quickly to the installation of 18 new nest boxes in northwestern Michigan cherry ( Prunus spp.) orchards between 2012 and 2013; they made nesting attempts (laid eggs) in 100% of boxes by 2015. In addition, kestrels that made nesting attempts in these boxes in 2013-2015 showed high reproductive rates: apparent nesting success was 91%, and mean number of fledglings per box with nesting attempts was 3.8. Also, kestrels were highly tolerant of both traditional monitoring techniques (opening the box) and newer camera technologies (a pole-mounted video camera and nest-box video cameras). Generalized linear modeling indicated that variables related to nest monitoring techniques and effort did not significantly affect daily survival rates for nests or brood size at fledging for successful nests; only hatching date had a small positive effect on brood size at fledging. These results suggest that orchard nest boxes have the potential to sustain or increase the breeding kestrel population in the region while increasing kestrel predation of crop-damaging prey in and around cherry orchards. This is promising for ongoing and future work with nest boxes in agricultural regions. [ABSTRACT FROM AUTHOR]